Point Grey Flea3 GigE Technical Reference
8 Flea3 GigE Attributes
8.2
Video Modes Overview
The camera implements a number of video modes, all of which allow the user to select a specific region of interest
(ROI) of the image. Some modes also aggregate pixel values using a process known as "binning". Specifying an ROI may
increase frame rate. Modes that perform binning may increase image intensity.
On Point Grey cameras, binning refers to the aggregation of pixels. Analog binning is aggregation that occurs before the
analog to digital conversion. Digital binning is aggregation that occurs after the analog to digital conversion. Unless
specified otherwise, color data is maintained in binning modes.
In most cases, pixels are added once they are binned. Additive binning usually results in increased image intensity.
Another method is to average the pixel values after aggregation. Binning plus averaging results in little or no change in
the overall image intensity.
Subsampling, or decimation, refers to the skipping of pixels.
Binning and subsampling reduces the effective image resolution. For example, 2x2 binning reduces both the width and
the height by half.
The figures below illustrate binning and subsampling. 2x vertical binning aggregates two adjacent vertical pixel values to
form a single pixel value. 2x horizontal binning works in the same manner, except two adjacent horizontal pixel values
are aggregated. 2x subsampling skips every second pixel horizontally and vertically.
Full Pixels
2x Vertical Binning
2x Horizontal Binning
2x Subsampling
Figure 8.1: Aggregation and Decimation of Pixels
Changing the size of the image or the pixel encoding format requires the camera to be stopped and restarted. Ignoring
the time required to do this in software (tearing down, then reallocating, image buffers, write times to the camera, etc.),
the maximum amount of time required for the stop/start procedure is slightly more than one frame time.
Moving the ROI position to a different location does not require the camera to be stopped and restarted, unless the
change is illegal (e.g. moving the ROI outside the imaging area).
Pixel correction
is not done in any of the binning modes.
Revised 10/29/2013
Copyright ©2010-2013 Point Grey Research Inc.
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